A liquid crystal panel, in which a liquid crystal is oriented by applying a voltage to a liquid crystal layer from pixel electrodes, to form an image on a display part, has been known.
A constitution of a conventional liquid crystal panel is briefly described below.
An element substrate comprises an insulating substrate having thereon a display part comprising thin film transistors and a peripheral circuit. The element substrate and a counter substrate are adhered by a sealing material with ensuring a gap between the substrates by a spacer. A liquid crystal is contained between the element substrate and the counter substrate.
The liquid crystal is sandwiched by the pair of substrates and surrounded by the sealing part.
As shown in FIG. 2, the sealing part of the panel is arranged to surround the display part or the display part and the peripheral driver circuit.
In the conventional constitution, the element substrate means a substrate in which an active matrix circuit and the peripheral circuit are provided. The counter substrate arranged as facing the element substrate, in which a counter electrode and a color filter are provided.
In the conventional constitution, a resin for sealing having an ultraviolet setting property or a thermosetting property is used as the sealing material.
An image sensor, on the other hand, has been widely used as an optical sensor converting an image to an electric signal in a copying machine, a digital still camera, a video camera and a facsimile machine.
Recently, a miniature system for incorporating an image and displaying the image is demanded. As a constitution meeting such a demand, a liquid crystal display device with which a sensor module such as a CCD is integrated is considered, but there are problems in consumption power (about 5 W), production cost and size.
The inventors of the invention intend to produce a liquid crystal panel and an image sensor on one substrate by using a MOS thin film transistor.
By using such a constitution, the apparatus can be miniaturized and of a low consumption power (about 50 mW) and low cost.
In the case where a liquid crystal panel and an image sensor are produced on one substrate, the arrangement of the panel and the image sensor and the constitution of the seal become important issue.
An object of the invention is to provide a liquid crystal display panel having a display part and an image sensor on one substrate, which has high reliability and an image sensor of low cost.